1. Technical Field
The present invention relates to an electro-optical device, such as a liquid crystal display or an organic EL (Electro Luminescence) device, and to an electronic apparatus, such as a mobile phone.
2. Related Art
An electro-optical device, such as a liquid crystal display, is widely used in an electronic apparatus, such as a mobile phone. For example, an electro-optical device is used as an image display unit of the electronic apparatus. A liquid crystal display serving as an electro-optical device is provided with liquid crystal serving as an electro-optical material interposed between a pair of substrates arranged so as to be opposite each other. An organic EL device serving as an electro-optical device is provided with an organic EL material serving as an electro-optical material on a substrate, and a protective member on the organic EL material.
A substrate for supporting the electro-optical material is formed of, for example, glass. The substrate may be subjected to impact when the electro-optical device or the electronic apparatus is accidently dropped, and may be damaged. In many cases, the boundary between two substrates arranged so as to be opposite each other in the liquid crystal display, or the boundary between the substrate and the protective member in the organic EL device may be damaged. This is considered to occur because stress becomes concentrated at the boundary.
A liquid crystal display 101 shown in FIG. 26A is taken into consideration. The liquid crystal display 101 has a large-area lower glass substrate 102, a small-area upper glass substrate 103, an upper polarizing plate 104 adhered to the outer surface of the upper glass substrate 103, and a lower polarizing plate 107 adhered to the lower glass substrate 102. A driving IC 105 is mounted in a planar portion of an extended portion of the lower glass substrate 102 outside the upper glass substrate 103, and an FPC (Flexible Printed Circuit) board 106 is connected to the edge portion of the extended portion.
The liquid crystal display 101 is received by a frame member, which is a part of the liquid crystal display 101, or by a receiving member, which is a part of an electronic apparatus using the liquid crystal display 101, in a portion indicated by a chain line X0, that is, in the surface of the upper polarizing plate 104. The surface indicated by the chain line X0 may be called a receiving surface. Typically, an interval of about 0.2 to 0.3 mm is formed between the receiving surface X0 and the surface of the FPC board 106. If the liquid crystal display 101 is accidently dropped and the surface of the liquid crystal display 101 on the upper polarizing plate 104 side collides against an obstacle, such as a floor, as shown in FIG. 26B, a bending load F is applied to the extended portion of the lower substrate 102, and tensile stress σ is generated at the boundary A between the lower substrate 102 and the upper substrate 103.
The tensile stress σ was analyzed by using simulation software, and the analysis result shown in FIG. 27 was obtained. That is, it could be seen that stress was specifically concentrated at a central portion B in a widthwise direction (a densely hatched portion) at the boundary A between the lower substrate 102 and the upper substrate 103. For this reason, when the bending load F was applied to the extended portion of the lower substrate 102, the substrate was easily damaged at the boundary A.
In order to prevent the substrate from being damaged, an electro-optical device is known in which epoxy resin is applied to the boundary between a pair of substrates arranged so as to be opposite each other, thereby reinforcing the boundary (for example, see JP-A-2006-227417 (p. 4 and FIG. 1). In such an electro-optical device, resin is applied to the edge portion where a crack is easily generated, thereby increasing stress resistance.
In the known electro-optical device disclosed in JP-A-2006-227417, resin is applied to a portion where a crack is easily generated, thereby increasing stress resistance in the corresponding portion. However, it is not sufficient to suppress occurrence of a crack when the electro-optical device is accidently dropped. In addition, when an impact is applied to the electro-optical device, it is necessary to suppress occurrence of large stress inside the electro-optical device, which causes a crack.